Whether it’s Sherlock Holmes or Star Trek’s Khan, Benedict Cumberbatch is known for portraying complex, nuanced characters. Still, the actor felt a particular responsibility to dig deep when it came time to play brilliant cryptographer Alan Turing—the British mathematician who deciphered Nazi codes during WWII and was later prosecuted for being gay—in The Imitation Game.

“He’s an exceptional man,” says Cumberbatch, who prepped for the role by perfecting Turing’s stuttering cadences and studying his correspondence with the mother of his high school crush. “I hope this film does justice to this unsung hero.”

The movie hits theaters Nov. 21 (or Nov. 14, if you fly to the U.K. to see it), but we procured a couple stills to hold you over.